BOOK IV. OF VESANIÆ; OR, OF THE DISORDERS OF THE INTELLECTUAL FUNCTIONS. CHAP. I. OF VESANIE IN GENERAL. 1528. THE Nosologists, Sauvages and Sagan, in a class of diseases under the title of VESANIÆ, have comprehended the two orders, of Hallucinationes or False Perceptions, and of Morositates or Erroneous Appetites and Passions; and, in like manner, Linnæus in his class of MENTALES, corresponding to the Vesaniæ of Sauvages, has comprehended the two orders of Imaginarii and Pathetici, nearly the same with the Hallucinationes and Morositates of that author. This, however, from several considerations, appears to me improper; and I have therefore formed a class of Vesaniæ nearly the same with the Paranoia of Vogel, excluding from it the Hallucinationes and Morositates, which I have referred to the Morbi Locales. Mr. Vogel has done the like, in separating from the Paranoia the false perceptions and erroneous appetites; and has thrown these into another class, to which he has given the title of Hyperæstheses. 1529. It is indeed true, that certain hallucinationes and morositates are frequently combined with what I propose to consider as strictly a vesania or an erroneous judgment; and sometimes the hallucinationes seem to lay the foundation of, and to form almost entirely, the vesania. But as most part of the hallucinationes enumerated by the Nosologists are affections purely topical, and induce no other error of judgment beside that which relates to the single object of the sense or particular organ affected; so these are certainly to be sepa rated from the diseases which consist in a more ge neral affection of the judgment. Even when the hallucinationes constantly accompany or seem to induce the vesania, yet being such as arise from internal causes, and may be presumed to arise from the same cause as the more general affection of the judgment, they are therefore to be considered as symptoms of this only. In like manner I judge with respect to the mo rositates, or erroneous passions, that accompany › vesania; which, as consequences of a false judg ment, must be considered as arising from the same causes, and as symptoms only, of the more general affection. There is, indeed, one case of a morositas which seems to induce a vesania, or more general affection of the judgment; and this may lead us to consider the vesania, in this case, as a symptom of an erroneous appetite, but will not afford any good reason for comprehending the morositates in general under the vesaniæ, considered as primary diseases. The limitation, therefore, of the class of Vesaniæ to the lesions of our judging faculty, seems from every consideration to be proper. The particular diseases to be comprehended under this class, may be distinguished according as they affect persons in the time of waking or sleeping. Those which affect men awake, may again be considered, as they consist in an erroneous judgment, to which I shall give the appellation of Delirium; or as they consist in a weakness or imperfection of judgment, which I shall name Fatuity. I begin with the consideration of Delirium. 1530. As men differ greatly in the soundness and force of their judgment, so it may be proper here to ascertain more precisely what error or imperfection of our judging faculty is to be considered as morbid, and to admit of the appellations of Delirium and Fatuity. In doing this, I shall first consider the morbid errors of judgment under the general appellation of Delirium, which has been commonly employed to denote every mode of such error. 1531. As our judgment is chiefly exercised in discerning and judging of the several relations of things, I apprehend that delirium may be defined to be,-In a person awake, a false or mistaken judgment of those relations of things, which, as occurring most frequently in life, are those about which the generality of men form the same judg ment; and particularly when the judgment is very different from what the person himself had before usually formed. 1532. With this mistaken judgment of relations there is frequently joined some false perception of external objects, without any evident fault in the organs of sense, and which seems therefore to depend upon an internal cause; that is, upon the imagination arising from a condition in the brain presenting objects which are not actually present. Such false perceptions must necessarily occasion a delirium, or an erroneous judgment, which is to be considered as the disease. 1533. Another circumstance, commonly attending delirium, is a very unusual association of ideas. As, with respect to most of the affairs of common life, the ideas laid up in the memory are, in most men, associated in the same manner; so a very unusual association, in any individual, must prevent his forming the ordinary judgment of those relations which are the most common foundation of association in the memory: and therefore, this unusual, and commonly hurried, association of ideas, usually is, and may be considered as, a part of delirium. In particular, it may be considered as a certain mark of a general morbid affection of the intellectual organs, it being an interruption or per version of the ordinary operations of memory, the common and necessary foundation of the exercise of judgment. 1534. A third circumstance attending delirium, is an emotion or passion, sometimes of the angry, sometimes of the timid kind; and from whatever cause in the perception or judgment, it is not pro portioned to such cause, either in the manner formerly customary to the person himself, or in the manner usual with the generality of other men. 1535. Delirium, then, may be more shortly defined, In a person awake, a false judgment, arising from perceptions of imagination, or from false recollection, and commonly producing disproportionate emotions. Such delirium is of two kinds; as it is combined with pyrexia and comatose affections; or, as it is |